Propeller



Nov. 7, 1950 E. H. RoUsE 2,528,609

PROPELLER Filed April 8, 1946 5 Sheets-Sheet 1 Il 49 I J1 M 52 I 53 l' g I es ,y v 99 103 M92 97% M |5l Nov. 7, 1950 E. H. RousE 2,528,609

PROPELLER Filed April 8, 1946 3 Sheets-Sheet 2 ,Minimum Nov. 7, 1950 Filed April 8, 1946 E. H. RoUsE 2,528,609

PROPELLER 5 Sheetsh-Sheet 3 Patented Nov. 7, 1950 PROPELLER Edward H. Rouse, St. Louis Park, Minn.

Application April 8, 1946, Serial No. 660,508

Claims.

My invention relates to propellers and has for .an object to provide .a propeller whose pitch may Ube readily varied to cause the propeller to operate efficiently under various loads. 5 An object of the invention resides in providing a hub and a number-of blades pivotally attached to -said hub for -swingingmovement in a manner .to vary the pitch of .the blades together with an adjusting member for holding the blades in adjusted position.

Another object of the yinvention resides in Yproviding an adjustablepropeller in which the pitch ofthe blades .throughout the working .portions thereof may be varied upon swinging of. the -blades in a manner to procure the most desir- .able -operating characteristics for the propeller under various loads.

A still further Aobject of the invention resides .in providing an adjustable propeller in which the pitch of the blades throughout substantially` the entire extent of the working portion thereof Vmay be maintained substantially constant at any adjusted position of the blades.

Another object of the invention resides in prov-iding a construction by means of which adjustment of the blades can be readily made without appreciable difficulty.

A still further object of the invention resides in providing -a propeller in which adjustment is positively maintained after having once been made.

,Other objects of the invention reside in the novel combination and arrangement of parts .and in the details of construction hereinafter illustrated and/or described.

In the drawings:

Fig. 1 is an elevational view of a propeller illustrating an embodiment of my invention and viewed from the aft end of the propeller.

Fig. 2 is a perspectiveview of the same.

Fig. 3 isa side elevational view of the propeller.

Fig. 4 is an elevational view of the propeller viewed from the tip of one of the blades.

Fig. 5 .is a sectional .view taken o-n line 5--5 of Fig. 1.

i Fig. 6 is a view similar to Fig. 5 showing the parts in altered position.

Fig. 7 is a sectional viewtaken on line l-l of Fig. l.

Fig. 8 is a sectional view taken on line 8-8 .of Figi. 5.

Fig. 9 is a perspective view of the hub of the propeller with the adjusting nut. mounted .thereon Y.

(Cl. 17m-7160.57)

Fig. 10 is adiagrammatic view illustrating the relation between the pitches of one of the blades at various localities along the working yportion of the same.

Fig. 11 is a plan view similar to Fig. l of a modification of the invention.

Fig. l2 is a view similar to Fig. 2 of the form of the invention shown in Fig. 11.

Fig. 13 is a view similar to Fig. 10 showing the.

relation of the pitches of one of the blades of the propeller illustrated in Figs. 11 and 12.

In variable. pitch propellers heretofore designed `where the medial line Aofthe blade coincides with the axis of the pivot for the blade, rotation of the blade .through a predetermined angle changes the pitch of the blade appreciably throughout the extent thereof. If, for example, the blade were designed for a live inch pitch throughout the extent of the working portion thereof and the said blade were rotated` to procure a pitch of three inches at the tip ofthe blade, the pitch near the shank of the blade would not change proportionally and would have a pitch of considerably lgreater Ythan the desired three inches. The instant invention provides a construction whereby `when diierent load requirements are met, the blades can be swung about their pintles so that the pitch of the blades is varied along .the extent thereof in a manner such that the blades operate in an efcient manner under all load conditions to which the propeller Vis `to be subjected.

My improved propeller comprises a hub ill to which are adjustably attached two propeller blades I! and l2. Since these blades are identical in construction, only the blade I i will be described in detail `and the same reference numerals, preceded by the digit 1, will be used to represent corresponding .parts v.of the blade l2. The propeller illustrated is a left hand propeller, rotating in a counter-clockwise direction as viewed .in Fig. 1.

The hub lll, as best shown in Figs. 5 and 9, comprises. a neck .I3 having a head EQ formed at the upper portion Aof the same. The neck i3 is constructed vwith threads l5 which extend up to within ashort distance of the head iii and where the same are cut back asdesignated at l5.' The vhead ill is in the form of a flange, being somewhat larger in diameter than the neck i3 and is provided with two planiform surfaces ,l1 and i8. .which serve a .purpose to be presently more.

fully described. lThe hub I0 is formed with a bore t3 through .u fhich the propeller shaft with which the propellerI isto be used may extend.

For the purpose of illustration, I have shown in the drawings a propeller shaft 2| having a reduced end 24 which fits within the bore I9. This construction provides a shoulder 22 which is received in a recess 23 formed in the lower end of the hub I9. A pin 21 extends through the shaft 2| at the locality of the shoulder 22 and is received in notches 28 formed in the hub I0. The reduced portion 24 of the shaft 2| is provided with threads 25 on which is screwed an acorn type nut 26 for holding the hub attached to the shaft.

The blade I2 is constructed with a tip portion 29, a working portion 3| and a shank portion 32.

The said blade has a trailing edge 6| and a leading edge E2. The shank portion 32 issues from an attaching member 33, the said parts being constructed integral. The attaching member 33 is provided with two bearings 34 and 35, which are disposed opposite one another andwhich straddle .the head I4 of hub I0. The` bearing 34 lies opposite the surface I1 of head I4, while the bearing 35 lies opposite the surface I8 of head I4. Extending through the head I4 of hub Ill is a hole 36 which is disposed on one side of the bore I9. The bearingf34 has a similar hole 31 which aligns with the hole 36, while the bearing 35 has a corresponding hole 38 extending into the same. The

' ,hole 39 is a blind hole, while the holes 3E and 31 extend completely through the respective parts in which they are formed. A pintle 39 extends through the holes 31 and 35 and into the hole 38 vand forms a pivot for supporting the blade'II during operation for swinging movement fromva position shown in dotted lines in Fig. 3 to a position shown in full lines in said gvure.

The blade I2 is similarly constructed and supported, being mounted onthe pintle |39 which is received in the hole |35` formed in head I4 on the side of the bore I9 opposite the hole 35.

The attaching member 33 is so constructed that a lip 4| is formed on the same adjacent bearing v35 and which lip overlies the end of the pintle |39. By means of this construction, the pintle is held in position and prevented from becoming .disengaged from the propeller during the operation of the same. When the blades are assembled, one blade, say blade I I, is first applied and pintle Y39 inserted into the holes 31, 36 and 38. The blade I2 is then applied and blade |I swung to a position beyond that shown in dotted lines in Fig. 3 so that lip 4| uncovers the hole |31. Pin I 39 may now be applied.

Adjustment of the propeller is procured by manually swinging the blades II and I2 about the pintles 3 9 and |39. The blades are held in adjusted position through the thrust exerted` against the same by the fluid in which the blades operate. This position is determined by means of a construction disposed within the attaching members 33 and |33. This construction consists of a nut 42 formed with threads 43 which are screwed upon the threads I of the hub I9. The lowermost end of the nut 42 has a knurl-ed portion 44 by means of which the same may be manually manipulated. Bey-ond this knurled portion,

4two slots 45 and |45 are formed in the nut which The attaching member 33 of blade II has formed on it a lug 52 which has a cam surface 53 adapted to engage the shoulder 5I on nut 42. 'I'he said lug is received within the slot 45 and the sides of the said lug are adapted to engage the end walls 49 of the outstanding members 41 and 48. By means of this construction, the nut 42 is held from rotation. It will readily be comprehended that advancing the nut 42 along the hub I9 will cause the shoulders 5I and |5| to engage the surfaces 53'and |53 of the blades II and I2 at different localities in a manner to hold the said blades in different angular positions with reference to the axis of the shaft 2|, as indicated in Fig. 3.k

For the purpose of protecting and shielding the nut 42 and the hub III, the attaching member 33 is provided with a shield portion 33 which extends about and partly covers the forward portion of the nut 42. v

Where a propeller is `desired in which the pitch remains the same throughout the extent of the y working portion of the blade upon vari-ous adjustments of the blade for pitch alteration, the blade is constructed as shownin Fig. l. In'this Iigure, the median line of the blade is indicated at 54.1 This line is determined by drawing various arcs 55, 56 and 51 through the blade with the axis 58 of the shaft 2| as center. y'Ihe lengths of the arcs 55, 56 and 51. between the trailing edge 6| and the leading edgev 62 arebisected and the points 63, 64 and 65 are procured. Line 54 is drawn through these points. I have foundthat when the line 54 along the workingl portion 3| .of

f' the' plateA is paralleltoa plane'indicated at .66

which contains the axis 5B and isY at right angles to the axis of the pintles 39 and |39 and when the entire working surface of the blade is situated Vwithin the space between this plane and a plane 61 at rightangles thereto and containing, the axis 58, that angular movement of the blade about the axis of the pintle 39 produced the same changes in the pitch of the blade throughout the working portion thereof. In other words, if the blade were designed to have a five inchr pitch throughout its extent when in the position shown in dotted lines in Fig. 3 and the same were adjusted to procure a three inch pitch by shifting thesame to th-e position shown in full lines in Fig. 3, the pitch would then be three inches throughout the entire extent of the working portion of the blade. This will readily become apparent from Figs. 1, 2 and 10. In Fig. 10, I have drawn three triangles 1I, 12 and 13 in which the bases 14, 15 and 16 are proportional to the circumferences of theY circles whose arcs are indicated at 55, 53 and 51 in Fig. 1 and which have the radii 11, 13 and 19 respectively. The altitudes 8|, 82 and 83 of these triangles (Fig. 1'0) have also been drawn proportional to the pitch of the blades at the points 63, 64 and 65 where the arcs 55, 56 and 51 intersect the median line 54 when the blade is positioned to procure maximum pitch. Since the pitch of the blade at the various localities specied is vconstant, then altitudes will all be equal. These triangles have been transferred to Figs. land 2 and Ylie in planes parallel to the4 axes 5,8 of the propeller shaft 2| and at right angles tothe radii 11, 13 and 19. The altitudes of these triangles contain the points 53,. 64 Yand 65 previously referred to. By projecting the triangles 1|, 12 and ,13 on a plane containing the median line 54 and parallel t0 the axis 58, other triangles'84,85 and are formed (Fig. 2) which have bases 81, 8,3 and 89 and hypotenuses 9|, 92 and 93, the altietudes 4'for "the 2corresponding triangles being vthe same. Ihe projection of these triangles on the *plane 541produces other triangles 94, 95 and A|36v `illustrated in Fig. l, whose hypotenuses are the "lines 14, -15 and'l andwhose valtitudes are 2|5, "2 I'Sand 2 I The bases-of these triangles are 'the T'bases-'81, 8'8 and-89 ofthe triangles 84,*85 and 86 jQFig. 2). By erecting construction lines Si', 98 Iandifl from the points 63,64- and 65 perpendicu- 'P-lar to the plane 66, other triangles are formedv Vwhich are indicated at li, ||l2 and |03. These A"trriangles have the radii '11, '18 and 19 ashyr-potenusesand portions of the'line S6 for altitudes. 'The bases ofthese Atriangles will be the construction lines 91,98 and 99. It will be noted that the sides of the triangles 94, 95 Yand 96 are at right "angles to the sides of the triangles lill, |52 and '133. The corresponding triangles are hence simi- `v"lan -Since the bases of the triangles IDI, |52 and ,|03 are equal, the bases 31, 88 and 89 of the tri- 'fangles 94, 95 and 96 are also equal. These bases "being'thebases of the triangles 84', 85 and 85, the 'said triangles are themselves equal. If now the blade be assumed to be rotated about pintle 39 through a certain angle, each of the hypotenuses 9h92 and 93 would rotate through an equal angle which .has been `represented in Fig. 2 by the shaded portions of the projected triangles 84, 1'8'5 and 86. Since these triangles are all equal, the reduction in the altitudes 8|, 82 and 83 is the same and the pitches of -th-e blade at the points 63, B4 and 65 are now reduced but are still equal. ,'Ihus, with my invention, the blade when adjusted :can be made to procure different pitches lwhich '.however remain lthe same throughout 'the Work- ;ingportion of the bladeat any one setting of the same.

The procedure adaptedwith reference to the points'a, 64 and 65 alsoapplies to any other se- .r-ries of points on the blade parallel to plane .436. It vis apparent that the further around the arcs 55, 56 and 51 that points' 63, 64 and 65 are located with respect to plane 66, the larger the projections 8l, 88 and 89 of the bases of the pitch triangles 14, and 'i6 will be. Therefore, the greater the pitch variation for a given angle of displacement of blade To secure more pitch Variation per given angular displacement of the blades, but still maintain equal pitch variation throughout the working portion of the blade, the blade must Ibe so shaped that median line 54 is still parallel to plane but further therefrom.

It frequently becomes desirable to slightly alter the pitch along the working surface of the blade from shank to tip, for example, to make the pitch greater at the shank of the blade and lesser at the tip of the blade to compensate for the additional slip lof the portions nearest the hub when operating under heavy thrust. A blade operating at high pitch and light thrust would have a pitch practically constant over the entire length of the blade from the shank to the tip, whereas the same blade when changed to operate at a lower pitch but with a higher thrust, the pitch should be less at the tip than at the shank. In Figs. 11, l2 and 13, I have shown a propeller designed with these characteristics. Inasmuch as the propeller and the various parts thereof are the same as illustrated in the other form of invention, the description will not be repeated but the same reference numerals with the letter a added thereto used to denote corresponding parts. It will be noted in Figs. 11 and l2 that the pitches of the blade at the designated localities are all the same for the high pitch setting of the blade. However,

Dwhen the-blade Ais swung ithrou'gh "the displa'ce- V`ment angle trepresentedebythe shaded area, the :pitches become vdifferent, .the Lremaining pitch nearest the shank of thelbla'de "being the greatjest. This is A.accomplished bysetting the blade ia w-ithrespect to pintle-ga so'that'its `median A=or average-line 54a Figs..l1.and 12) 'is at an angle --top'l-'ane 65a. By this `means .it is possible to secure a .greater .pitch change at the tip than at Lthe shank and thus compensate for additional slippage of the central portion of the workingsection' of the blade as increased thrust` is yde- 'manded of it as pitch is reduced.

In the design of propeller blades it becomes desirable to increasethe pitch at .the trailing edge fas compared to the pitch at the leading edge.

'This `increase is preferably greater for low pitch blades `working :under high thrust than for vhigh pitch blades working under low thrust. Withtmy invention, this result is procured since the trailing edge is nearest the plane 65 and decrease of 'the-pitch* ofthe blade by rotating it on "its pintle will reduce the pitch nearest the line 66 less rapidly'thanvfarther from said line as ypreviously 'explain-ed.

I have found in the ldevelopment Iof my invenftion" that the workingiportionvof the blade should be wholly confined to the space between the Yplanes and 61. Also, I have 'found that the vmedian line 54 is best located nearer the plane B6 than the plane 6l and that said line be either parrallel vto or form a-slight angle withthe plane 66 in accordance with the characteristics of the blade desired. For Ordinary use, ari-'angle of approximately l5 degrees between median line 54a 'and .plane a is quite suitable.

'Where different pitches are desire'd along the median line, a curved m-edian line will be usedinstead of a straight ilne.

While `I have described the invention as adapted for use in water, it can readily be corn- Yprehended that the propeller may alsobe used 'in air, and that the same will give the desired results regardless of the medium in which it is used.

The advantages of my invention are manifest. The propeller is extremely simple in construction and can be readily adjusted. A propeller constructed in accordance with my invention operates efficiently at all of the adjusted positions at which the same may be set within the range of adjustment of the blades. The same propeller can be us-ed for light loads traveling at relatively high rate of speed and for heavy loads traveling at a lower rate of speed. Thus, a single propeller can be furnished for a specified motor which propeller can be adjusted to meet all load requirements.

Changes in the specic form of my invention, as herein described may be made within the scope of what is claimed without departing from the spirit of my invention.

Having described my invention what I claim as new and desire to protect by Letters Patent is:

1. In a propeller, a hub, a swinging blade carried thereby, an attaching member at the inner end 0f the blade, pivot means acting between said attaching member and hub and disposed in proximity to the axis of said hub, said pivot means having its axis at right angles to a plane containing the axis of said hub, a part of the median line of said blade at the outermost portion thereof being disposed within the space between said plane and a plane containing the axis of the hub and at right angles to the first plane, said portion of the median line of the blade forming an outwardly diverging'angle of between 12 and 15 with vsaidV rst plane said portion of the median line i1 extended intersecting therirst named Vplane outwardly of said hub.

2J InY a propeller, a hub, a swinging blade carried thereby, an attaching member adjacent said hub and from which said blade extends, pivot -means for the blade acting between said attachv"ingmember and hub and disposed in proximity f'to. the axis of said hub, said pivot means having its axis at right angles to a plane containing the -axis of said hub, axially progressing threads formed on the exterior of said hub, a nut screwed on said threads and having a beveled shoulder, a lug on said attaching member engaging said .shoulder to hold the blade in adjusted angular position, and an outstanding portion on said nut providing a wall for engaging said lug to restrain 'rotational movement of the nut.

' 3. In a propeller, a hub, a, swinging blade carto the axis of said hub, said pivot-means having its-axis at right angles to a plane containing the laxis of said hub, axially progressing threads formed on said hub, a nut screwed on said threads, a shoulder on said nut, a projecting part .on the attaching member for engagement with said shoulder to hold the blade in adjusted anfgular position, and an outstanding portion on ',saidattaching member having a wall for engaging and looking said nut for rotation.

, 4. In a propeller, a, hub, a swinging blade car-t ried thereby, an attaching member adjacent said hub and from which said blade extends, pivot means vlfor the blade acting between said attaching member and hub and disposed in proximity to the axis of said hub, said pivot means having .its axis at right angles to a plane containing the -axis of said hub, axially progressing threads 8 formed on said hub, a nut screwed on sai threads, a manipulating portion on the nut, a

, slot formed in said nut beyond the manipulating portion and providing at the end of the same a shoulder and on each side thereof axially projecting portions, a lug on said attaching member adapted to enter said slot when the blade is swung in one direction and to seat against said shoulder, said lug being engagea'ble with said axially projecting portions to restrain turning of the nut. .Y

' 5. In a propeller, a hub, a plurality of Swingin blades carried thereby, an attaching member for each blade, said attaching members having spaced bearings receiving said hub, one of the bearings of each blade and the hub having aligning through holes, the other of said bearings having blind holes communicating with and in alignment with the corresponding holes in the hub,r pintles in said holes for supporting said blades for swinging movement relative to said hubs and a lip on each of the bearings having the blind holes and adapted in certain positions of the blades to overlie the exposed ends of the pintle of the juxtaposed'blade.

EDWARD H. ROUSE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number l Name Date 866,369 Learnard Sept 1'7, 1907 2,192,034 Y Y Driggs Feb. 27, 1940 2,219,288 Avery Oct. 29, 1940 2,282,436 Taylor May 12, 1942 FOREIGN PATENTS Number Country Datev u 768,964 France May 28, 1934 799,403 France Apr. 4, 1936 Certificate of Correction Patent No. 2,528,609 November 7, 1950 EDWARD H. ROUSE It is hereby certied that error appeors in the printed specification of the above numbered patent requiring correction as follows:

lColumn 7, line 34, for the word for read from;

and that the said Letters Patent shouid be read as corrected above, so that the same may conform to the record of the case in the Patent Ooe. Signed and sealed. this 23rd dey of January, A. D. 1951.

THOMAS F. MURPHY,

Assistant ommz'ssz'oner of Patents. 

